COUNT results from SQL Query with a HAVING clause

Question

Are you able to use COUNT in a query with a HAVING clause so that the COUNT returns the number of rows? When I try, Im getting the count of the number of times the ID shows up in the table. Here is the query:

SELECT col_appid, min(col_payment_issued_date) as PayDate  
FROM tbl_ui_paymentstubs  
WHERE isnull(col_payment_amount,0) > 0  
GROUP BY col_appid  
HAVING min(col_payment_issued_date) >= '09/01/2010' and min(col_payment_issued_date) <= '09/30/2010'

I get back 6 rows, which is fine, but i'd like to just get back the number 6.

I found I could do it this way, but was wondering if there was another, more elegant way:

WITH Claims_CTE(AppID, PayDate) as
(  
 SELECT col_appid, min(col_payment_issued_date) as PayDate
 FROM tbl_ui_paymentstubs
 WHERE isnull(col_payment_amount,0) > 0
 GROUP BY col_appid
 HAVING min(col_payment_issued_date) >= '09/01/2010' and min(col_payment_issued_date) <= '09/30/2010'
)  
 SELECT count(AppID) as Amount from Claims_CTE

`

Answer 1

Using COUNT with a GROUP BY clause will provide a count for each group. If you want the count of the number of groups, it will have to be a separate query (like your CTE example).

I would just use a simple subquery, instead of the CTE:

SELECT COUNT(*) FROM 
 (SELECT col_appid, min(col_payment_issued_date) as PayDate  
  FROM tbl_ui_paymentstubs  
  WHERE isnull(col_payment_amount,0) > 0  
  GROUP BY col_appid  
  HAVING
     min(col_payment_issued_date) >= '09/01/2010'
     and min(col_payment_issued_date) <= '09/30/2010') Claims

Answer 2

You can also use a sub-query.

SELECT count(*) as Amount
FROM (
    SELECT col_appid FROM tbl_ui_paymentstubs
    WHERE isnull(col_payment_amount,0) > 0
    GROUP BY col_appid
    HAVING min(col_payment_issued_date) BETWEEN '09/01/2010' AND '09/30/2010'
) Claims